David Hufford is a professor and the director of The Doctors Kienle Center for Humanistic Medicine at the Penn State College of Medicine, where he has appointments in medical humanities, behavioral science, and family and community medicine. He is also an adjunct professor of religious studies at the University of Pennsylvania, and he is currently leading an initiative to develop a Center on Spirituality and Health at Penn’s School of Medicine. He won a Templeton Foundation Faith & Medicine Award in 1995, the first year of that program to support religion and health courses in medical schools, and he has taught that course to fourth-year medical students since that time. His research is centered on the ethnographic and phenomenological study of the beliefs of ordinary people, especially those beliefs that are in competition with the positions of official institutions. His inquiry has focused on the experiential grounds for spiritual beliefs, and the role of reason in their development and persistence. He has also sought to understand the widely held notion that science and spiritual belief are contradictory. His publications have primarily been concerned with describing the grounds for spiritual belief, showing their reasonableness, and questioning the assertion that, beginning with the Enlightenment, science has made religion outdated and not rationally defensible. His book The Terror That Comes in the Night considers beliefs about spiritual evil that are found all over the world within the context of scientific research on sleep paralysis.